Scientists at MIT have made a groundbreaking discovery in the field of semiconductors, developing a razor-thin crystal film that allows electrons to move at unprecedented speeds. Published in a recent study, the physicists utilized a process called molecular beam epitaxy to create a 100-nanometer-wide film from a crystalline material known as ternary tetradymite.
The film’s exceptional electron mobility, measured at 10,000 centimeters squared per volt-second (cm^2/V-s), is seven times faster than traditional semiconductors. In comparison, electrons typically move at a rate of about 1,400 cm^2/V-s. This remarkable conductivity opens up possibilities for more efficient and powerful electronic devices that generate less heat and waste less energy.
The researchers likened the properties of the film to a “highway without traffic,” emphasizing its potential for creating sustainable electronic devices capable of performing more work with less power. Applications for this technology include wearable thermoelectric devices that convert waste heat into electricity and “spintronic” devices that utilize electron spin for information processing.
To measure electron mobility, the scientists placed the crystalline film in a cold environment and subjected it to a magnetic field. By passing an electrical current through the film, they observed fluctuations in electrical resistance, known as magnetoresistance. Even the slightest defects in the material can hinder electron movement, underscoring the importance of refining the film creation process for optimal results.
The team at MIT believes that further advancements can be made by perfecting this material and creating even thinner films, as well as exploring proximity coupling for use in future spintronics and wearable thermoelectric devices.